Consider the input types that may exist on a mixing console. I found all of these on units sitting around the shop...

October 18, 2011, by Pat Brown

Almost every Syn-Aud-Con seminar has attendees from other technical fields that need to learn about sound systems and audio.

These fields include networking, telephony, lighting, electrical and others.

Many tell us that audio is the most confusing thing they have encountered in their technical careers – and it is no wonder.

Consider the input types that may exist on a mixing console. I found all of these on units sitting around the shop.

There are nine (9) analog topologies and twelve (12) digital topologies. Each serves a purpose. Each works fine for its intended application. Each is defensible from a technical and practical point-of-view. Each will likely remain in use as other connector types and topologies emerge.

Consider also that some of these have several variations, such as the polarity convention on an XLR connector or AES3 on a DB25 connector.

It is ironic that digital I/O is often touted as making things easier, yet there are more digital connector types than analog! Add to this the confusion caused by the need to configure digital I/O for the correct sample rate, bit-depth, etc.

It’s no wonder that noise and distortion remain the weak links of most sound systems. They often result from feeding the wrong signal to the wrong jack.

We have all heard a DVD player over-driving a microphone input. Yes, you get sound, but in audio the presence of sound does not necessarily mean that you hooked it up right.

A modern digital mixer may be able to convert between any of these formats.

The signal may come in as some form of analog and go out as some form of analog or digital.

The user must often choose based on the required cable length, input options on the next device or some other criteria.

So not only does the audio tech have to understand the connectors and interface topologies, he must also know the characteristics of the devices at the other end of the cable.

The interconnect is the easy part. Consider the knowledge and experience required to configure a DSP for a 3-way loudspeaker.

Technical complexities aside, the most perplexing part of audio for non-audio people is the artistic side. While some levels can be set with voltmeters and analyzers, many other adjustments are based on subjective criteria – you just turn the knob until it sounds right. But what is right? There can be any number of “rights.” How confusing is that!

The really good audio people have strong theoretical and practical backgrounds. They have “must have” tools in their toolbox that you can’t buy anywhere. They have the ability to diagnose many system problems by just listening to a speech track played over the system. They can often make it sound way better by turning one knob a little bit.

Their personal study time may be divided between Sound System Engineering, product manuals and Einstein’s papers on relativity, and they understand that all three are completely relevant to what they do.

Most importantly, they know that they will never know it all.

Yes, audio is confusing. Background in another technical field can help, but learning audio is a life-long process.

Pat and Brenda Brownown and operate SynAudCon, conducting training seminars around the world in addition to providing in-depth web-based training.